Enhanced thermoelectric performance in c-axis oriented Ca₃Co₄O₉ films by Ag addition through multiple annealing

Abstract

The [Formula: see text]-axis oriented Ca3Co4O9 (CCO) films without and with 5 wt.% Ag addition were prepared by chemical solution deposition (CSD) through multiple annealing processing on single crystal LaAlO3 (001) substrates. With Ag addition, the resistivity at 300 K is decreased to 2.25 m[Formula: see text]cm, the Seebeck coefficient at 300 K is enhanced to 106 [Formula: see text]V/K and the power factor at 300 K can reach as high as 0.5 mW[Formula: see text]K[Formula: see text]m[Formula: see text], which is the highest value among CCO films prepared by CSD. The results suggest that Ag addition is a very effective route to improve the thermoelectric properties of CCO films through multiple annealing processing.